Electronic mail messaging and other network communications via computerized communications networks is widespread. In addition to responsible, desirable use of such communications, there is an increasing use of such communications, particularly e-mail messages, for sending undesirable unsolicited messages, primarily for commercial purposes. Bulk unsolicited commercial e-mail (“UCE”) messages are typically referred to as “spam.” Spam senders and other irresponsible senders of messages (collectively, “spammers”) may send UCE messages easily and inexpensively, and thus tend to send as many as desired. In contrast, message recipients, their messaging systems, and any intermediate messaging systems, bear virtually the entire processing and financial burdens for transmitting all such messages. Accordingly spammers may, at will, undesirably burden messaging systems, e.g. by using network bandwidth, mail server and other messaging system resources, by sending as many messages as they desire.
Current mail messaging systems have no adequate way to ensure Quality of Service (“QoS”) and/or priority treatment of electronic mail (“e-mail”) processing. For example, QoS problems often arise in the context of spam attacks—i.e. large mass mailings of UCE messages. A common method for sending spam is the “dictionary attack.” Another common method for sending spam is the “brute force” method in which various alphanumeric combinations are tried for selected domains, whether the addresses are known to be valid or not. This creates a particularly heavy burden on communications network resources. This unfettered use effectively results in theft and abuse of mail messaging system resources of messages receivers. Enterprise networks, government and public agency networks, as well as Internet Service Providers, are particularly adversely affected.
Traditional attempts to control undesired e-mail messages involve the use of messages filters, which typically operate at the SMTP level, i.e. at the Application Layer of the OSI seven layer model. Such filters are configured to take one of four actions with respect to each incoming message, namely, Deliver the message to the intended recipient, Delete the message, Reject the message during the SMTP protocol conversation, or Quarantine the message (typically by delivering to an alternate computer file folder for human review). These filters, termed “DDRQ” filters, may conserve resources at the client device, but they are not effective for limiting the impact of UCE on the recipient's or any intermediate network/messaging system resources. In other words, such filters are inadequate for preventing the theft and abuse of the network/system resources (including server capacity, software licenses, administrative/processing time, network infrastructure, bandwidth, storage, etc) necessary to receive, process and filter each message along the network in the process of delivery the message to the end user/the end user's messaging system. For example, even if a DDRQ filter rejects an SMTP message during the SMTP protocol conversation, that message still uses up to 90% of the network/messaging system resources that would have been consumed had delivery to the intended recipient been completed.
Additionally, the processing work performed and the network resources required increase proportionally to the total volume of messages received. In other words, spammers that send UCE to a recipient that is using a traditional DDRQ filter effectively necessitate an increase in capacity of the filter infrastructure, along with the rest of the impacted messaging system's network resources, as a result of the spammers' behavior. Failure to scale system capacity to accommodate the spammers' sending rate results in overloading of the network's resources and loss of legitimate communications. Accordingly, spammers' activities directly impact the effectiveness and/or costs of recipients' and intermediaries' messaging systems. This is particularly alarming in view of the observed growth in UCE volumes. Increased costs of implementing and/or maintaining messaging systems are felt particularly heavily by corporations and other enterprises that rely heavily on e-mail messages, and that support a large number of recipients/e-mail addresses.
Of particular concern is the observed behavior of spammers when faced with DDRQ filtering. Such spammers typically respond to increasing DDRQ filter effectiveness by increasing their own outgoing message volumes in order to maintain or grow their total responses and resulting profits. This is thought to be a key component of the current upswing in UCE volume growth rates since spammers realize that a DDRQ filter that is anything less than 100% efficient will allow an increased amount of spam to reach intended recipients as UCE volumes increase.
What is needed is a system and method for controlling distribution of network communications that reduce the burden on network resources of recipients and intermediaries and/or allows for distribution of network communications in a controlled manner.